USE OF FTIR AND THERMOGRAVIMETRIC ANALYSIS OF ANCIENT MORTAR FROM THE CHURCH OF THE CROSS IN GERASA (JORDAN) FOR CONSERVATION PURPOSES

The present study intends to assess the performances of two kinds of ancient mortar in the Church of the Holy Cross Gerasa in Jordan. The conservation of ancient construction requires a worthy characterization of the most significant mortar components before starting the conservation, after the results obtained, and during the restoration process of the ancient site to decide how to react. The objective of this work is through FTIR perform experimental contribution to study the influence of organic part on the mechanical behavior of mortar (construction and conservation) and to minimize the risks of low tensile strength. Nowadays it is becoming increasingly important to apply the new techniques for sustainability and compatibility issues to conserve the historical monuments, particularly from increasing deterioration in the mortar's joints of the church. New results obtained concerning the identification of the binding materials of mortars, in particular the proteinaceous material (Egg-White) used in the church, and to collect more information to be used for the compatibility, which will be applied for the first time in Jordan. Furthermore, the results will make a new approach in Jordan to accept it in the field of restoration. It concludes that it is easy to identify all the organic part components of the mortar using the Fourier transformation infrared spectroscopy (FTIR) in the band of the organic material between 1480-1420 cm-1), supported by thermogravimetric analysis (TGA)/ (DTA peak at around 250 ºC). The investigations of both methods yielded precise information about mortar production technology and revealed an additive proteinaceous material in the mortars.